浅析注浆封孔测定煤层瓦斯压力误差问题

实践中,测定煤层瓦斯压力的方法有多种,均存在一些误差。该文探讨了通过注浆封孔测定瓦斯压力过程中每一个环节存在的误差,然后提出了通过用钻孔变径等进行密封效果检验措施,希望能够不断降低测定误差,使瓦斯压力测定的准确性不断提高,为实践提供参考依据。     

承压三相泡沫瓦斯压力测定仪

瓦斯压力测定一直是个难题,尤其在煤层里测定更是难以保证。通过分析和模拟直接测定法中钻孔与封孔器之间的流体泄漏形式和影响因素,开发了承压三相泡沫瓦斯压力主动式测定仪,对煤层钻孔的裂隙有较好的密封,现场试验效果良好,取得了四钻孔平行测定、高度一致的好成绩。     

本煤层瓦斯压力测定新技术研究

为了提高本煤层钻孔原始瓦斯压力的测定精度,根据煤层钻孔周围应力分布规律,探讨了煤层钻孔封孔装备和封孔材料性能,研究了在不具备施工穿层钻孔的地质条件下,采用煤层钻孔来测定瓦斯压力.经过试验,确定了在普通硅酸盐水泥中掺入质量分数为5%的铝酸盐水泥作为煤层瓦斯压力测定的封孔注浆材料,并采用胶囊、复合材料、聚氨酯综合封孔工艺,...     

封孔等待时间对瓦斯压力快速测定的影响

煤层瓦斯压力的测定除了与煤层的原始瓦斯压力、煤层的透气性大小和围岩等自然因素有关外,还与封孔效率、封孔工艺及封孔质量等人为因素有关。文章研究了钻孔形成后到钻孔密封生效这段时间的长短对瓦斯压力快速测定的影响,用有限差分法和FORTRAN对测压钻孔瓦斯流动方程进行数值计算,得出封孔等待时间的长短对快速测压的影响。     

极薄煤层瓦斯基本参数测定实践

汪洋煤矿沿煤层布置巷道开采近水平极薄煤层,从现有煤层巷道往底板施工专门考察巷道,布置测定瓦斯压力钻场和钻孔,在提高封孔工艺技术和连接接头密封质量的基础上,灌注高压氮气主动式测压,较短的时间测定瓦斯压力成功率达80%,在四川省首次测到须家河组煤层瓦斯压力最高值为2.25MPa,该技术对极薄煤层瓦斯抽采基本参数的测定具有重要指导意义。     

复杂地质条件下测压钻孔的几种封孔工艺

煤层瓦斯压力的准确测定能够为矿井制定合理有效的防治瓦斯灾害措施提供依据.在复杂地质条件下进行瓦斯压力测定,封孔质量的好坏将直接影响着煤层瓦斯压力的测定情况.通过对矿井复杂地质条件下煤层瓦斯压力测定的实践,经过分析和总结,在煤层瓦斯压力测定中取得了上向钻孔和下向钻孔封孔工艺的新认识,为在复杂地质条件下采取合理的测压封孔工艺提供了参考,可更好地指导矿井煤层瓦斯基本参数的测定,为更好地确定瓦斯治理方案提供可靠的依据.     

长距离钻孔快速测定煤层瓦斯压力技术

针对胶囊粘液封孔测定煤层瓦斯压力受到钻孔长度限制的现状,在快速测定煤层瓦斯压力的基础上,对胶囊粘液封孔长距离钻孔快速测定煤层瓦斯压力的可行性进行了分析,研究了封孔端孔口大、测压气室孔口小的新技术。现场应用该技术取得了良好的效果。     

测压钻孔瓦斯涌出的规律

煤层瓦斯压力的测定是有效防治矿井灾害事故发生的重要基础性工作,但压力的测定受煤层埋藏地质条件的复杂性和瓦斯压力测定技术的局限性,煤的变质程度、破坏类型、透气性、瓦斯压力等的差异各个钻孔周围的瓦斯流场不尽相同,使其准确、真实的测定煤层瓦斯压力较为困难.为了能弄清钻孔瓦斯涌出机理,通过分析煤层瓦斯流动理论,建立了测压孔周围煤体内瓦斯流动的均质径向稳定流动模型,找出了测压孔周围三维空间内瓦斯流动规律以及压力分布规律.结果证明,测压孔内瓦斯压力分布曲线为双曲线形.     

主动式煤层瓦斯压力测定技术改进

为了准确测定煤层真实的瓦斯压力,对主动式煤层瓦斯压力测定技术进行了改进,由过去测压钻孔一次成孔改为注浆后二次成孔。现场应用表明,测压钻孔二次成孔技术提高了测压结果的准确性和可靠性,缩短了测定时间,为煤层瓦斯压力的快速准确测定提供了良好的技术支持。     

钻孔瓦斯释放时间对煤层瓦斯压力测定的影响分析

钻孔被动式注浆法是目前国内测定煤层原始瓦斯压力的主要方法之一。从钻孔见煤到封孔以及安装压力表这段时间内,理论上煤层释放瓦斯对测定煤层瓦斯原始压力有一定的影响。通过实际分析及理论研究对这部分瓦斯所产生的压力进行计算,对所测定的煤层瓦斯压力进行了修正。     

New approximation for a magnetic field of a dipole on a borehole axis

New, more exact approximated solution to the direct problem of identifying a signal of a vertically oriented magnetic dipole on a borehole axis is reported. This solution makes possible to process the data of the high-frequency induction logging isoparametric sounding, including negative values of the measured phase difference. The new approximation enables taking into account the variable borehole radius that is of special importance when a highly-conductive drilling mud is used. As the obtained expression is explicit, it can be used for the quick data processing and for solving inverse problems of the borehole geophysics. __________ Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 4, pp. 3–9, July–August, 2006.     

Three-dimensional modeling of a deposit in a database

Institute of Mining, Siberian Branch, Academy of Sciences of the USSR, Novosibirsk. Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 4, pp. 77–85, July–August, 1991.     

Deformation of a blocky medium around a working

Conclusions The deformation of the blocky mass around a working can be interpreted as displacement of the material in a convergent radial channel with an aperture angle of 360°. A kinematic scheme permitting the formulation of the problem in statically determined form (similar to the classical scheme for calculation of the pressure of the earth at a supporting wall) is constructed. Axisymmetric solutions for different levels of block interaction on contact are given. Estimates of the carrying capacity are obtained in the case of rigid-plastic contact between the block and in conditions of dry friction. It is shown that this scheme admits of transition in the limit to the accurate solution of the Lame problem in the continuum formulation. Cases in which increase in the relative slip between the blocks leads to decrease in the interaction force between them (weakening) are considered. With slight weakening, the deformation is a stable process. If the weakening is greater than a critical level, the solution becomes unstable, which indicates the uncontrollable release of stored elastic energy from the mass. Institute of Mining, Siberian Branch, Academy of Sciences of the USSR, Novosibirsk. Translated from Fiziko-Tekhnicheskie Problemy Razrabotki Poleznykh Iskopaemykh, No. 6, pp. 7–15, November–December, 1990.